[insonable]

gorsuch is complaining that if california restricts its in-state sales based on xyz, then firms everywhere will optimize in ways influenced by requirements xyz. with california being quite a lucrative market, its requirements will thus have influence over producers everywhere if they intend to sell to california. presumably if it were a more inconsequential state setting some requirements, then gorsuch wouldn't have so much of a problem and might go along. roberts points out that this is against the spirit of states having equal sovereignty. in other words, you can't let wyoming set requirements abc because who cares about that market, and then turn around and tell california "you're too big to set requirements xyz" and have that seen as fair.